Stacker crane power lift mechanism



Nov. 22, 1966 M. J. DECHANTSREITER 3,

STACKER CRANE POWER LIFT MECHANISM 5 Sheets-Sheet 1 Original Filed Dec. 24, 1964 M 0 H 1 WR n VB W. N Z Y A E w M A X W m w R H m NOV- 2, 966 M. J. DECHANTSREITER 3,

STACKER CRANE POWER LIFT MECHANISM Original Filed Dec. 24, 1964 5 Sheets-Sheet 2 v INVENTOR. MAX J. DE CHANTSREITER 1966 M. J. DECHANTSREITER 3,

STACKER CRANE POWER LIFT MECHANISM 5 Sheets-Sheet 3 Original Filed Dec. 424, 1964 INVENTOR. MAX J. DECHANTSREITER HTfORNEY Nov. 22, 1966 M. J. DECHANTSREITER STACKER CRANE POWER LIFT MECHANISM Original Filed Dec. 24, 1964 5 Sheets-Sheet 4.

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I l l l l I l INVENTOR. MAX J. DE CHANTSRE/TER Z. WW4

1966 M. J. DECHANTSREITER 3, 8

STACKER CRANE POWER LIFT MECHANISM 5 Sheets-Sheet 5 Original Filed Dec. 24, 1964 INVENTOR. MAX J. DE CHANTSRE/TER AffOR/VEY United States Patent and this application Nov. 10, 1965, Ser. No. 507,206 1 Claim. (Cl. 212-128) This is a divisional application of the co-pending US. patent application Serial No. 420,908 filed December 24, 1964, entitled, Stacker Crane, which issued on May 10, 1966, as Patent No. 3,250,399.

The present invention relates generally to material handling devices and, more particularly, to travelling cranes supported by overhead rails and having a vertical, rigid, telescoping mast on which a load carriage is vertically moveable. These devices are sometimes referred to as stacker cranes.

The present invention provides an overhead travelling crane of the vertical, telescoping mast type, which has an improved and highly eflicient load lifting system. This aspect of the invention is particularly desirable and necessary in large sizes of stacker cranes. More specifically, the load mast is connected directly to the main or rigid mast, which permits the use of only one cable system for supporting the load. In other words, the load is imposed directly on the supporting, rigid mast. As a result, the intermediate telescoping mast then only requires a small and relatively light cable system and it is used only to guide or keep the intermediate mast in proper relationshi to the load mast; this lighter or secondary cable system performs no load lifting function but serves only to carry the weight of the intermediate mast and insures that the relative, proportionate, vertical speed between the load mast and intermediate mast is always the same.

These and other objects and advantages of the present invention will appear hereinafter as this disclosure progresses, reference being had to the accompanying drawings, in which:

FIGURE 1 is an elevational view of a stacker crane made in accordance with the present invention, certain parts being shown as broken away or in section for clarity in the drawing, and the crane shown in the full retracted or up position;

FIGURE 2 is a plan view of the crane shown in FIG- URE 1, certain parts being shown as broken away;

FIGURE 3 is a section view taken along line 33 in FIGURE 1 on an enlarged scale;

FIGURE 4 is an. elevational view of a portion of the or ane shown in FIGURE 1, taken from line 4-4 in FIG- URE 1, certain parts being removed for clarity;

FIGURE 5 is a cross sectional view taken along line 55 in FIGURE 2, but on an enlarged scale;

FIGURE 6 is a diagrammatic view of the primary cable lifting system;

FIGURE 7 is a diagrammatic view of the lifting means for the operators cab;

FIGURE 8 is an enlarged, fragmentary View of a portion of the upper end of the cab mast shown in FIG- URE 1, with certain parts removed for clarity;

FIGURE 9 is a view taken along line 99 in FIG- URE 8, certain parts being removed or broken away for clarity;

FIGURE 10 is a sectional view taken along line 1010 in FIGURE 8; and FIGURE 11 is a View of a portion of FIGURE 9, but showing the cab in the mast locking position.

Referring in greater detail to the drawings, a pair of overhead rails 1 and 2 are provided in spaced apart rela- 3,286,853 Patented Nov. 22, 1966 tionship and on which the entire crane C is supported for travel between the rails. These rails are suitably mounted in any conventional manner, not shown, as for example, as part of an overhead runway structure or building structure.

Trolley frame A trolley T has a series of wheels 3 which ride along and are guided by rails 1 and 2, the wheels being suitably journalled in the two parallel, frame members 4 and. 5. A large, rectangular, steel plate 6 is welded across the upper sides of members 4 and 5 and other steel plates 7 and 8 are also welded to members 4 and 5, all forming a rigid trolley frame. The trolley is driven along the rails in either direction by an electric motor 9 through the drive box 9a and the drive shaft 9b on which some of the wheels 3 are fixed. A brake 9c is also provided for the mot-or.

The trolley also includes a large circle or ring 10 which, as shown clearly in FIGURE 5, is comprised of an upper ring plate 10a and a lower, ring plate 10b parallel thereto, an inner, vertical ring wall 10c and an outer vertical ring wall 10d, all welded together to form the ring 10 having a rectangular cross sectional shape.

The ring 10 is secured to the horizontal plate 6 of the trolley frame by a series of eight horizontal bars 12, two on each side of the frame, as clearly shown in FIGURE 2. These bars are secured by nuts 13 to brackets 14 welded to the plate 6, and to brackets 15 welded to the periphery of ring 10. By this means the ring 10 is prevented from moving horizontally relative to plate 6.

Means are also provided, as will now be described, for vertically supporting the ring 10 on plate 6 in such a manner that the load on the crane can be weighed.

Four load weighing cells 17 are located in circumferentially spaced relationship on top of plate 6 and the plates 18 of the ring 10 rest on top of these cells. Thus the cells act to read the weight of the load carried by the crane, as will appear later. The load cells cannot tolerate any side loading and the horizontal bars 12 insure that side loading of the cells does not occur.

Upward movement of the ring 10 relative to plate 6 is limited by the four vertical bolt means 19 extending therethrough. These bolt means, however, do not restrict downward, weighing movement of the ring 10 relative to plate 6.

Turntable A turntable 20 is carried on the trolley frame for rotation about a central, vertically disposed axis. This turntable carries a downwardly depending mast assembly which will be described later and which rotates together with the turntable as a single unit about this vertical axis.

The turntable includes a large, horizontal, circular, steel plate 21 which is rotatably supported by the large, anti-friction, bearing ring assembly 22 located on the top of ring 10. Assembly 22 includes an inner race 22a secured to the underside of the turntable, an outer race 22b secured to the upper side of ring 10, and a series of balls 220 located between the races in the conventional manner to carry vertical and horizontal thrust components.

Located on top of the turntable is the conventional electric motor 23 connected by the drive reduction unit 24 to the cable drum 25. A brake 26 is located between the motor and drum, and an eddy current brake 27 is connected with the motor, for purposes that will appear later.

Mast assembly A mast assembly 30 is rigidly fixed to the underside of the turntable and extends downwardly therefrom. The mast assembly includes rigid mast R welded to an upper plate 29 and two large gusset plates 31, 32 are welded between mast R and plate 29 for rigidity and reinforcemerit. Plate 29 is then in turn rigidly secured to turntable plate 21 by bolt means 29a. The assembly also includes a shorter, intermediate mast I which slides up and down on the long mast R, and also includes a load mast L which can be vertically positioned relative to the intermediate mast. As shown in FIGURE 3, these masts are rectangularv in cross section and nested together in telescoping relationship. More specifically, a pair of rollers 33 are mounted by bolt means 34 along each of the opposite sides of the load mast R and are held captive and guided in their vertical movement by the pairs of rails 35 (FIGURES 3 and 4) fixed to the opposite sides of intermediate mast R. Similarly, a pairof rollers 36 are mounted by bolt means 37 along each of the opposite sides of load mast L for being guided by the pairs of opposed rails 38 fixed to the opposite sides of the intermediate mast I.

Other pairs of rollers 44 (FIGURE 4) are mounted on the opposite sides of the load mast about horizontal axes and rotate in abutting relationship with the intermediate mast to provide guiding and stabilizing therebetween in a direction parallel to the axis of rollers 36. Reinforcing gusset plates 45 are welded to the mast L and to the bracket mounting 44a for rollers 44.

The-load mast may have a lift fork unit 50 vertically adjustable along the pair of vertical rails '51 by means of a hydraulic cylinder 52 connected between the unit 50 as at 52a (FIGURE 4) and :the load mast as at 52b. The rails .51 are of T shape cross section and are welded along [their length to the load mast.

Power lift In accordance with one aspect of the invention, a cable lifting system is provided directly between the load mas-t EL and the rigid mast R. 'I his multiplesheave system imposes the entire load directly on the turntable with-out g ing through the intermediate mast I. This system is shown diagramatically or in a spread out manner in FIGURE 6.

More specifically, a plurality of sheaves 60 are rotatably mounted on the upper end of the rigid mast R and a plurality of sheaves -62 is also rotatably mounted directly on the load mast L. A cable 63 is attached to .the drum 25 at each of its ends and trained around sheaves 60 and 62 as shown.

As shown in FIGURES 1 and 4, there is also provided a flexible member connection between the three masts R, I and L but this connection does not perform any function of lifting the load. Instead it serves to transmit the weight of the intermediate mast I to the rigid mast, and keeps the intermediate mast in proper relationship to the load mast and rigid mast. 1

This flexible member connection includes a pair of sheaves 65, 66 rotatably mounted at the lower end of the.

intermediate mast I, having a cable 67, 68 respectively, trained therearound. These cables 67 and 68 are deadened to the rigid mast R at 69 and 70, respectively, and to the load mast at 71 and 72, respectively. This system insures thatthe relative proportionate vertical speed between the load mast and intermediate mast remains the same. For example, if the load mast moves at ten feet per second, then the intermediate mast move at one- Lhalf that speed, namely, five feet per second.

The present arrangement requires only one cable lift system to carry the entire load and only a lightweight flexible litt connection is required to support the intermediate mast and coordinate its movement with the load roast.

Operators cabFIGURES 1 and 3 The cab mast assembly is shown in FIGURE 1 in the fully retracted or up position and is shown for illustrative purposes only as comprising 'two telescoping mast members, namely a fixed inner mast 80 rigidly secured at 4 its upper end to the rigid mast and which extends downwardly to terminate at 80a. The second member is an outer mast 82 which telescopes over the inner mast. cab is rigidly attached to the outer mast for vertical movement therewith.

The members .80 and 82 are mounted together as follows.

each of the opposite outer sides of the inner mast. Pairs of rollers 85 are mounted on the inside of each of the opposite sides of the outer mast and these rollers engage.

opposite sides of the adjacent rail.

Other rollers 88, disposed on axes ninety degrees to those of the rollers 85, are rotatably mounted on opposite sides of the outer mast 82 and roll against the rails 84. By means of these rollers 85 and 88, a guiding support in all directions is provided between the inner and outer masts as they telescope relative to one another.

FIGURE 7 is a schematic diagram of the lifting arrangement for .the cab. 'Ilhe cab is vertically positioned by a hoist drum 90 (FIGURE I) mounted on the trolley frame and two sheaves 91 and 92 mounted on the outer mast 82. A pair of cables 93 and 94 are fixed at one of their ends to the drum, and are then trained around the sheaves-91 and 92 and then deadened .to an equalizer bar 95. Bar 95 is pivotal mounted at 96 on the trolley frame.

Stops 92a and 96b prevent excessive movement of the bar 95. A measure of safety is provided by the use of two cables and an equalizer bar because, in the event one cable breaks, the other will hold'the cab.

Furthermore, broken rope safety devices forthe load are not necessary to insure safety of the operator. load cable breaks, it is not necessary to catch a twenty: live ton falling load for example, and instead the load can be permitted to fall without damaging the crane and/or its supporting structure.

Cab safety device A broken rope safety device is provided for catching the operators cab in the event a hoist cable breaks, and this device is shown in detail in FIGURES 8 and 9. The 1 mounting for each of the sheavm 91 and 92 is similar and one will be described. A sheave bracket 97 is pivotally mounted on the shaft 98 fixed on the upper end of mast member 82. Brackets 97 have slots 99 in each of their slides through which a bar 100 extends loosely. Bar 100 is welded to the upper end of mast 82 and is normally 1 contacted by micro-switches 101 and 102 carried on .the sheave brackets.

If the cable 91 is not broken and the cab mast operating normally, the brackets are pulled upwardly against the bar'100. If the cable 93 breaks, either one or both of the brackets 97 instantly drops, carrying the switches with them and away from contact with bar 100. This action opens either one or both of the switches which in turn deenergize solenoids 104. De-energizing of 'a solenoid causes downward shifting of its link 105 and causes its cam 106 to be rota-ted from the mast unlocked position slrown in FIGURE 9 to the mast locked position shown in FIGURE 11. l the cams are in the FIGURE 11 position, they bind or lock against the inner mast member 80 and lock the outer mast member 82 thereagainst it.

The cams are suitably journalled on their shaft 107 and extend through slots 108 in the outer mast member .82. An overtravel slot 109 is provided in link 105 and arm 110 fixed to shaft 107 has a pin 111 fixed thereto which travels in this slot. Thus, the solenoid 104 can return freely to its normally energized position. cam to its normal running, unlocked position where its flat, clearance portion 113 permits free movement between the mast members 80 and 82.

Various modes of carrying out the invention are contemplated as being within the scope of the following claim particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

The

Guide rails 84 are secured one along the length of Ifa.

Spring 112 returns the What is claimed is:

An overhead travelling crane having a turntable rotatably mounted about a vertical axis, a downwardly extending, telescoping mast assembly secured to said turntable and for vertically positioning a load carried by said assembly, said assembly comprising a rigid mass secured to said over-head crane, a rectangular in cross section intermediate mast mounted around said rigid mast in telescoping relationship therewith and vertically movable relative to said rigid mast, an elongated and rectangular in cross section load mast having means to support a load, said load mast mounted around said intermediate mast and vertically movable relative to said inter-mediate mast, power lift means mounted on said nrntable and connected directly to said load mast for imposing the weight of the load directly on said rigid mast and aifeeting vertical movement of said load mast, said power lift means including a power Winch drum on said turntable, sheaves mounted on the outside of the upper end of said elongated load mast, and a flexible cable connecting said drum and 20 said sheaves; a flexible connection between said intermediate mast,said rigid mast, and said load mast, said flexible lift connection comprising sheaves mounted on and adjacent the lower end of said intermediate mast, cable means trained amound said sheaves and dead-ended on the rigid mast and on and within the load mast, whereby vertical movement of said load mast causes vertical movement of said intermediate mast in the same direction but at a lower speed.

References Cited by the Examiner UNITED STATES PATENTS 2,925,888 2/1960 'Kagel 187-9 2,947,426 8/1960 Ooteswonth et a1. 212128 3,111,227 11/1963 Lofquist 212-128 3,144,137 8/1964- V-alliere et 21212'8 3,174,634 3/1965 Peck 214-75 FOREIGN PATENTS 1,060,787 7/ 1959 Germany.

ANDRES H. NIELSEN, Primary Examiner. 

